Four million trees will be planted over the next year, the UK government said as it confirmed it would continue to fund the creation of new woodlands.

Some £6m will be invested by the government in new planting in 2014-15, as part of a £30m investment for woodlands in England, with the remainder of the money being spent on management of existing woods.

The funding will create 2,000 hectares (5,000 acres) of new woods. Ministers also said new grants for planting trees were planned from 2015.

Conservationists welcomed confirmation that funding of woodland creation schemes would continue - something which had been unclear until now - but warned that the level of planting the government had pledged to maintain was too low.

Plans for creating 2,000 hectares of new woodland in 2014-15 falls far short of the government's own aspiration to create 5,000 hectares of new woodland (12,000 acres), the Woodland Trust said.

The commitment was set out in the government's forestry policy for England, developed in the wake of the aborted plans to sell off or hand to charities all of the country's public forests which provoked widespread outcry.

The Woodland Trust also raised concerns about threats to existing woodland such as development, and the possibility that developers could be allowed to cut down ancient woodland if they "offset" the damage with new planting elsewhere.

Funding for tree planting in the next two years had been in doubt due to changes in forestry funding schemes, hitting already-low planting rates in England and stopping nurseries growing saplings for future years, the Woodland Trust said.

Forestry minister Dan Rogerson said: "Forests are a cherished national resource, which provide precious habitats for wildlife and natural spaces for generations to enjoy.

"Planting 4 million trees over the coming year will help us to extend woodland cover which will benefit wildlife, improve the environment and help grow the economy.

"New forests hold economic, as well as environmental and social benefits, enabling the forestry businesses to create more jobs and play an increasing role in the nation's economic recovery."

Hilary Allison, Woodland Trust policy director, said the trust was encouraged by news that the environment department would continue to provide funding for new planting through woodland creation grants in 2015 and beyond.

"This funding is vital to ensure enthusiasm among landowners and communities is harnessed and the momentum to plant new woods in England is not lost," she said.

But she said the 2014 commitment to plant 2,000 hectares of woodland fell far short of the 5,000 hectares a year needed to reach a target for 12% of England to be covered in forests, a goal set out in 2013 in the government's forestry policy. The commitment would also see planting rates fall to a 10-year low.

"At just 10%, England still has one of the lowest rates of woodland cover in Europe.

"It faces huge threats from disease and development with even the government's current planning policy guidelines and its high speed rail project undermining protection for irreplaceable ancient woodland," she added.